OPINION ON REHEARING EN BANC
I. BACKGROUND
Defendant-appellant Leonard Jackson pleaded guilty to possession of ammunition after conviction of a felony in violation of 18 U.S.C. § 922(g)(1). Initially Jackson was charged in a three count indictment for the possession of four firearms, the possession with intent to distribute approximately one gram of cocaine, and the possession of ammunition by a felon. The firearms and cocaine counts were dismissed as part of the plea agreement. The government also agreed not to seek enhancement of Jackson’s sentence pursuant to the Armed Career Criminal Act, 18 U.S.C. § 924(e)(1). The court sentenced Jackson to sixty months’ imprisonment and imposed a special assessment of fifty dollars. At the time of Jackson’s initial sentencing, the district court believed the Sentencing Guidelines were unconstitutional and declined to follow them.
Following an appeal of this sentence,' we remanded the case for resentencing pursuant to the Guidelines in light of Mistretta v. United States,
Jackson again appealed, claiming the district court misapplied the Guidelines in departing upward. Specifically, he alleged the district court erred because: (1) the second sentence constituted a more severe penalty in violation of the double jeopardy clause, (2) the facts did not warrant an upward departure from the Guidelines range, and (3) the degree of departure was unreasonable. A panel of this court affirmed the district court in United States v. Jackson,
We granted Jackson’s request for a rehearing en banc solely on the issue of the reasonability of the district court’s degree of departure. We find the district court’s explanation of the degree of departure inadequate. We reverse and remand for a clear explanation of the reasons for the degree of departure from the Guidelines.
II. DISCUSSION
A. The General Goals of the Sentencing Guidelines
Congress adopted the Sentencing Guidelines to promote uniformity and proportionality in sentencing. Uniformity in sentencing entails treating similar cases alike. United States Sentencing Commission, Guidelines Manual, Ch. 1, Pt. A, intro, comment., at 1.2 (1989). Proportionality refers to treating different cases differently, or having the sentence fit the crime. Id. The Guidelines provide sentencing ranges of point values. The Guidelines also assign point values to offense characteristics and the defendant’s criminal history. See U.S.S.G. § 1B1.1 (1990). Convictions involving roughly equivalent offense characteristics and defendants with similar criminal histories thus receive substantially uniform sentences.
The Sentencing Commission has established a strong presumption in favor of using of the Guidelines in sentencing. See, e.g., U.S.S.G. Ch. 1, Pt. A, intro, comment., at 1.5. The Commission recognizes, however, that despite its best efforts it cannot account for all aspects of every case. See, e.g., id. at 1.6. The Commission therefore provided for departures from the Guidelines range. A sentencing court may depart from a Guidelines range based on: (1) offense characteristics not considered by the Commission, U.S.S.G. § 5K2.0; United States v. Baker,
B. Rules Governing Departures
1. Departures in General
The Commission recognizes an inherent tension between the principles of uniformity and proportionality. U.S.S.G. Ch. 1, Pt. A, intro, comment., at 1.2. It also recognizes this tension is largely irresolvable.
Two rules governing departures secure the principles embodied in the Guidelines. First, departures should rarely occur. Id. at 1.6-7. Because Congress set uniformity and proportionality as goals, a sentencing judge should depart from the Guidelines range only when necessary. See United States v. Aguilar-Pena,
Second, when a sentencing court departs from the Guidelines, the court’s discretion, though considerable, is not unfettered. See United States v. Dean,
The court also must explain the departure sentence adequately. See, e.g., 18 U.S.C. § 3553(c) (court must state reasons for imposing particular sentence); United States v. Freitekh,
2. Degree of Departure
We are concerned here with the question of how to determine whether a district court’s degree of departure is reasonable. On appeal, we review the reasonableness of a district court’s explanation of the departure from the Guidelines range in light of the Guidelines’ purposes. See, e.g., Dean,
[T]he district court’s proferred justifications, as well as such factors as ... the seriousness of the offense, the need for just punishment, deterrence, protection of the public, correctional treatment, the sentencing pattern of the Guidelines, and the need to avoid unwarranted sentencing disparities.
White,
The first of these factors—the district court’s proferred reasons for the degree of departure—is an absolute requirement. As we held in Freitekh, “the court must indicate its reasoned basis for the degree of departure.”
Although in White we listed multiple factors that inform our reasonableness inquiry, the district court there gave objective reasons for the departure sentence by analogizing to a higher criminal history category as the Guidelines recommend.
The other indicia of reasonableness discussed in White are germane because they relate to the uniformity and proportionality of the sentence. As we observed in Gardner: “Reasonableness requires that the sentence regard the guideline factors ... of uniformity and proportionality.... These principles are not limited to sentences within the guideline range, but obviously are meant to apply to sentences that depart from the guideline range as well.”
3. Departure Sentence Based on an Inadequate Offense Level
When a sentencing court finds aggravating circumstances relevant to sentencing that the Commission did not adequately consider, the court may depart upward from the Guidelines range in imposing a sentence.
Although formulas of mathematical exactitude are neither required nor possible, the district court should articulate the objective criteria used as a basis for determining the actual sentence imposed. In many instances, this will consist of an extension of or extrapolation from other guideline levels or principles, or use of an analogy to other closely related conduct*991 or circumstances that are addressed by the guidelines.
The universe of potential crimes may seem infinite, but all crimes are composed of different combinations of a limited number of basic offense characteristics. A sentencing court should be able to find some treatment of most offense characteristics in the Guidelines. In drawing analogies to other levels and the principles of the Guidelines to determine the proper degree of departure, a sentencing court generally may follow one of two basic approaches. Simply adding to the defendant’s offense level the points assigned in the Guidelines to analogous conduct is the more straightforward approach. Alternatively, a court may “treat the aggravating factor as a separate crime and ask how the defendant would be treated if convicted of it.” Ferra,
We do not require the sentencing court to assign offense level points to aggravating circumstances as the Commission would have if it had considered them. See Dean,
4. Departure Sentence Based on an Inadequate Criminal History Category
When a sentencing court finds the criminal history category computed under the Guidelines “significantly under-represents the seriousness of the defendant’s criminal history or the likelihood that the defendant will commit further crimes,” the court may depart from the Guidelines range. U.S.S.G. § 4A1.3, p.s. A district court has considerable discretion in appraising a defendant’s criminal history. The court may consider the defendant’s present or past criminal conduct as grounds for departure to a higher criminal history category. See Fortenbury,
The reference should not be mechanical. A district court need not exhaust in sequence each higher criminal history category. Contra United States v. Kim,
C. Departure from the Sentencing Guidelines in This Case
With these considerations in mind, we turn to an examination of the district court’s departure from the Guidelines
In support of the departure sentence, the district court first found there were “aggravating circumstances of a kind and to a degree not adequately taken into consideration by the Sentencing Guidelines.” Although during the original sentencing the district court had expressed concern about cocaine and drug paraphernalia found in Jackson’s apartment and firearms found in the apartment building, the court did not mention these factors as aggravating circumstances during resentencing. The court next remarked “[t]he criminal history category does not adequately reflect the seriousness of your past conduct,” citing several prior convictions the Guidelines excluded because they were more than fifteen years old. See U.S.S.G. § 4A1.2(e). The district court stated the sentence should take these convictions into account because they demonstrated a continuing course of criminal conduct. The court then noted Jackson had received lenient treatment in a prior conviction for shooting with intent to kill. Finally, the court expressed concern over the relationship between drugs and violence in Jackson’s criminal history.
The district court offered no further explanation for the sentence it imposed. The court only offered its reasons for departing but did not provide any justification for the degree of departure. The court did not rely on the Guidelines to find analogous levels and principles to guide its degree of departure. The court failed to clarify whether the departure was based on aggravating circumstances the Commission did not adequately consider, underrepresented criminal history factors, or both.
Moreover, the district court apparently abandoned the Sentencing Guidelines entirely by imposing a sentence beyond the range appropriate to category VI. Both the language and the structure of the Guidelines discourage such departures except in extraordinary circumstances. The Sentencing Commission expressly has stated that departures beyond category VI are reserved for the unusual “case of an egregious, serious criminal record in which even the guideline range for a category VI criminal history is not adequate to reflect the seriousness of the defendant’s criminal history.” U.S.S.G. § 4A1.3, p.s. The structure of the Guidelines sentencing table also indicates a departure beyond category VI should be highly unusual. A comparison of the two axes of the sentencing table is instructive. See id. Chapter 5 Part A, at 5.2. The offense level axis lists values from one to forty-three. If a sentencing court reaches level forty-three — either by applying the Guidelines directly or by analogizing — and finds that level inadequate, the court must depart beyond the highest level. In contrast, the criminal history axis is open-ended. A defendant with thirteen or more criminal history points is placed in category VI. This feature of the table illustrates the Commission intended that a sentencing court reaching the uppermost criminal history category generally should stay within its confines.
In the rare situation when a sentencing court has examined category VI and can articulate reasons for that sentence’s inadequacy, two alternative reference points within the Guidelines could help guide a departure beyond the limits of the Guidelines. First, the increments between the Guidelines ranges could assist both the sentencing court and the reviewing court in gauging the reasonableness of the degree of departure. Observing the point value assigned to various criminal history elements and the way they move one upward through the criminal history categories could help the court determine an appropriate analogue sentence. See United States v. Schmude,
Of course, we do not impose either of these two approaches as a mechanical formula limiting a district court’s exercise of discretion. See Russell,
III. CONCLUSION
We do not hold the district court in this case could not adequately explain the particular sentence it imposed. It is not our task to determine what a district court’s explanation for a departure could be. Congress has assigned that task to the district courts. We execute Congress’s intent in requiring the district courts to adequately explain any departure sentence. Only if a district court provides a sufficient explanation will we uphold a sentence as reasonable. We hold the district court did not adequately explain the degree of departure from the Guidelines and that it must do so. We therefore VACATE Jackson’s sentence and REMAND to the district court for an explanation of the departure sentence in accordance with this opinion.
Notes
. It is important to note, however, that departure sentences will reflect the principle of uniformity to the extent they are proportional. If a departure sentence fits the crime in one case (i.e., it is proportional), then it will seem appro-pílate in a comparable case (i.e., it will promote uniformity). Treating different cases in roughly the same "different” way transforms the tension between the Guidelines’ goals into synergy.
. See, e.g., United States v. Davis,
. At the time of Jackson’s second sentencing, the judge could consider aggravating circumstances in deciding to depart and in determining the degree of departure only if they were related to the charged offense. See U.S.S.G. § 5K2.0 (1989). We express no opinion whether this relationship existed in this case. We note, however, that the 1990 amendments to the Guidelines eliminate the requirement that the aggravating circumstances be related to the charged conduct. Id. § 5K2.0 (1990); id. at App. C.201.
. In determining and explaining a departure sentence, the sentencing court must expressly distinguish between the two possible grounds for departure. United States v. Fortenbury,
